fullscreen を切り替えるライブラリ

fullScreen.js

export function enableFullScreen() {
  const doc = window.document;

  return (
    doc.fullscreenEnabled ||
    doc.webkitFullscreenEnabled ||
    doc.mozFullscreenEnabled ||
    doc.msFullscreenEnabled
  );
}

export function isFullScreen() {
  const doc = window.document;

  const ret =
    doc.fullscreenElement ||
    doc.webkitFullscreenElement ||
    doc.mozFullscreenElement ||
    doc.msFullscreenElement;

  return ret;
}

export function toggleFullScreen() {
  const doc = window.document;
  const docEl = doc.documentElement;

  const requestFullScreen =
    docEl.requestFullscreen ||
    docEl.mozRequestFullScreen ||
    docEl.webkitRequestFullScreen ||
    docEl.msRequestFullscreen;
  const cancelFullScreen =
    doc.exitFullscreen ||
    doc.mozCancelFullScreen ||
    doc.webkitExitFullscreen ||
    doc.msExitFullscreen;

  if (
    !doc.fullscreenElement &&
    !doc.mozFullScreenElement &&
    !doc.webkitFullscreenElement &&
    !doc.msFullscreenElement
  ) {
    requestFullScreen.call(docEl);
  } else {
    cancelFullScreen.call(doc);
  }
}